370HENDEESON'S HANDBOOK OF PLANTS EHI leet, and gained a position considerably in advance ol their parent trunks. Alter this, fewer additions are made to the roots, but the head begins to expand in every direction, spreading Its branches on all sides. 'These branches, in their turn, send downlong, slen¬ der roots, like those ol the Banyan Tree {Ficus Indica), which, rapidly elongating, de¬ scend Irom all heights, and reaching the water, penetrate the mud, becoming in time, independent trees. Thus a complicated laby¬ rinth Is at length lormed." The Irult ol the spedes is edible, and its fermented juice is made into a light wine. In Borneo a coarse, bitter salt Is extracted Irom their aerial roots.Rhizophora'ceae. A natural order ol tropical trees or shrubs, with opposite, entire leaves and axiUaiy flowers, closely allied to Gombre¬ tacem and Lythracem. The order contains about lourteen genera, the chiel ol which are Halopdalum and Rhizophora.Rhoda'nthe. From rhodon, a rose, and anthoa,' a flower; In allusion to the color ol the flower- heads. Nat. Ord. Compoaitm. A very beautilul genus ol hall-hardy an¬ nuals lound In western Australia. R. Man¬ glesii and Its varieties have white, rose, crim¬ son, and purple flowers. These plants are admirably adapted lor the border in summer, or the conservatory or green-house in winter, as they come into flower early, and continue tor a long time. The flowers, II gathered when young and dried in the shade, -will re¬ tain their beauty during the winter, making them valuable lor bouquets ol dried flowers. For perfection ol growth in the border, the seed should be sown In March in the green¬ house or a hot-bed, and caretully grown on in small pots until all danger from Irosts is past, when they may be turned out into the open border. For winter flowering the seed should be sown in August or September. Introduced by Capt. Mangles in 1832.Rbo'dea. See Rohdea.Rhodio'la. From rhodon, a rose. Nat. Ord. Crassulacem. A genus ol succulent plants, separated from Sedum, on account ol their bearing fertile and barren flowers on distinct plants.Rhodochi'ton. A genus ol Scrophulariacem, differing but little from Lophospermum, the calyx being less divided and the corolla not so open. R. voMdle, Is an Interesting and uselul climber either lor the green-house or lor sum¬ mer decoration in the flower-garden. It can be increased by cuttings or seeds. Introduced from Mexico In 1833.Rhodode'ndron. Bose Bay. From rhodon, a rose, and dendron, a tree. Nat. Ord. Ericacem. A genus ol well-known evergreen shrubs and low-growing trees, remarkable lor their beautilul flowers and thick, luxuriant, glossy foliage. The species are widely diffused, be¬ ing indigenous to the United States, Europe, Asia, and the Indies. Some ol the species are perfectly hardy, and others require the pro¬ tection ol the green-house. 01 our native species R. maximum (Great Laurel), common from Maine to Ohio, is a tall-growing shrub, with leaves Irom lour to ten inches long, very thick and glossy. The flowers are a Ught rose color, nearly white, with greenish throat. EHO and spotted with yellow or Ught red. R. Gatawbiense, common on the AUeghanles from Pennsylvania southward. Is perfectly hardy, and flowers most prolusely. It seldom grows above lour leet high, but lorms a symmetri¬ cal shrub, exceedingly ornamental lor a lawn plant. This species is the parent ol all our hardy varieties, having been hybridized with the Nepal species, R. arboreum. From this cross there has been raised a great number ol beautilul kinds, most ol which are hardy in the latitude ol New York. The varieties in¬ clude colors from nearly pure white to dark crimson. All the hardy sorts are ol easy cul¬ ture, growing Ireely in almost any Inamy soil, but they prefer a moist situation, protected from cold winter winds. When flrst planted they should be mulched with any convenient material that will prevent evaporation and keep the roots moist and cool. Several flne spedes have been Introduced Irom the Hima¬ layas, a lew ol them bearing but littie resem¬ blance to the common Bhododendron, one be¬ ing a climber. The plants are propagated by seeds, cuttings, layers, or by grafting. Azalea, and Rhodora, are included In this genus by Bentham and Hooker.Rhodole'ia. From rhodon, a rose; alluding to the color ol the flowers. Nat. Ord. HamameU- R. Ghampioni is a beautilul green-house shrub, rivalling the Camellia, but ol a very curious structure. It lorms a small, ever¬ green tree, but would probably blossom Ireely as a shrub. The leaves are alternate, elliptic- ovate, bright green above, glaucous beneath. The flower-heads grow at the ends ol the branches, and are two inches and a hall in diameter, ol a beautilul rose color, enclosing a large number ol stamens. These heads usually consist ol flve flowers. It is a native ol China, growing In the woods about Hong Kong. Introduced In 1850.Rtaodomy'rtus. Prom rhodon, a rose, and myrtoa, myrtle; In allusion to the rose-colored flowers, and its alliance to the Myrtle. A genus ol Myrtacem, containing a lew spe¬ cies ol trees or shrubs, natives ol Eastern Australia, tropical Asia, and the Indian Archi¬ pelago. R. tomentoaa, the only cultivated spedes, known as the HUl Gooseberry, and Indian Hill Guava, has ovate-velvety leaves, do-wny beneath, and beautilul rose-colored flowers. Introduced from China in 1776, under the name ol Myrtus tomentoaa.Rhodo'ra. From rhodon, a rose; alluding to the color ol the showy flowers. Nat. Ord. Ericacem. R. Canadensia, the only species, is a hand¬ some, low-growing shrub, with oblong, de¬ ciduous leaves, whitish and downy under¬ neath ; the sho-wy, rose-purple, rarely white flowers appearing rather earlier-than the leaves. It is a native ol cold woods and swamps. New England to Pennsylvania, and northward on the mountains. Included by Bentham and Hooker under Rhododendron.Rbodotha'mnus. From rhodon, a rose, and thamnoa, a shoot or branch. Nat. Ord. Erir- . cacem. This genus consists ol a solitary species, lound In the Alps ol Europe, and long known as Rhododendron Chamaedatua. It is a pretty, dwarl, almost prostrate, evergreen shrub,